Magnesium has gained a lot of attention due to its inherent properties such as light-weight with a density of 1.7 g/cm³ and the highest strength to weight ratio. Such unique properties make magnesium a suitable candidate for various applications including vehicles, aerospace projects, construction, energy storage applications and medical implants. One of the crucial issues with the use of magnesium on these applications is the tendency of the material to corrode. This is due to the high chemical activity of magnesium, its standard equilibrium potential of Mg/Mg²⁺ is -2.4 V vs. NHE. To prevent these problems, there have been reported strategies such as formation of alloys with noble metals or inert elements and the protection of the metal with a coating film.¹ From the mentioned solutions, the most suitable solutions to prevent corrosion on magnesium without compromising its properties are the formation of alloys using passive elements such as Al, Ni or Cr and the protection of magnesium with a coating film. ^2,3

Based on these two solutions, we propose to use aluminum as the second element for the alloy formation to prevent corrosion of magnesium and to enhance its structural, thermal, and electrical performance. In our study, we’ve been able to produce magnesium alloys by electro-co-deposition which have demonstrated to have a lower corrosion behavior compared to pristine magnesium films. Similarly, magnesium-based materials are gaining interest in energy storage application due to two-electron transfer per a reaction and thus a high volumetric capacity compared to the state-of-art Li-ion batteries. Also, they have shown to be safer than Li since Mg during cycling do not form dendrites.⁴ Herein, we explore the use of electro-co-deposited Mg-Al alloy as electrodes to construct high energy rechargeable Mg batteries.

References

(1) Esmaily, M.; Svensson, J. E.; Fajardo, S.; Birbilis, N.; Frankel, G. S.; Virtanen, S.; Arrabal, R.; Thomas, S.; Johansson, L. G. Fundamentals and Advances in Magnesium Alloy Corrosion. Prog. Mater. Sci. 2017, 89, 92–193.

(2) Liu, R. L.; Scully, J. R.; Williams, G.; Birbilis, N. Reducing the Corrosion Rate of Magnesium via Microalloying Additions of Group 14 and 15 Elements. Electrochim. Acta 2018, 260, 184–195.

(3) Yuwono, J. A.; Birbilis, N.; Liu, R.; Ou, Q.; Bao, Q.; Medhekar, N. V. Aqueous Electrochemical Activity of the Mg Surface: The Role of Group 14 and 15 Microalloying Elements. J. Electrochem. Soc. 2017, 164 (13), C918–C929.

(4) Bucur, C. B. Challenges of a Rechargeable Magnesium Battery A Guide to the Viability of This Post Lithium-Ion Battery, 1st editio.; Spinger Briefs in Energy, 2018.